Firing mechanism for firearms



p 13 59%, G. N. ALBREE 2,407,526

FIRING MECHANISM FOR FIREARMS Filed 001;. 21, 1944 8 5 5 WW3 .iw

Patented Sept. 10, 1946 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to firearms and particularly to the ignition system, that is, to the elements employed for detonating the chambered cartridge.

In order to give an understanding of the invention I have illustrated it herein as it might be embodied in an automatic arm of the straight inertia blowback type, the breech of which is kept closed while the bullet is in the barrel by the inertia of the heavy bolt coupled with its recoil spring.

It should be understood, however, that the invention is not limited in its use to firearms of the abov type, as certain features of the invention are equally applicable to arms of other types.

One object of the invention is to provide a firearm in which the firing pin is connected to a rocking member that is carried by the bolt and which has rocking engagement with a rockersuppo-rting face with which the breech closure is provided, together with means for rocking said member over said face to produce the detonating impact of the firing pin, the construction being such that during such rocking motion of the rocking member, the lever arm thereof that carries the firing pin has a progressively increasing length as said rocker is actuated, whereby the forward impact-producing movement of the firing pin relative to the bolt is an accelerated movement which increases the hammer-blow effect of the firing pin in detonating the primer.

A further object of the invention is to provide a novel means for cushioning the impact of the bolt against the breech face when the bolt is closed.

Further objects of the invention are to provide a relatively simple ignition system comprising few and rugged parts and to otherwise improve the cartridge-detonating means of a firearm in the particulars hereinafter set forth.

In the drawing:

Fig. 1 is a fragmentary sectional view showing a firearm embodying my invention,

Fig. 2 i a section on the line 2-2, Fig. 1.

Fig. 3 is a section on the line 3-3, Fig. 1.

Inasmuch as the invention relates to the means for detonating the cartridge, I have not thought it necessary to illustrate herein a complete firearm. but have only shown a sufficient portion of such an arm to permit my invention to be understood.

In the drawing 4 indicates the receiver of a firearm and 5 is the breech end of the barrel which is mounted in the receiver, said barrel having the cartridge-receiving or firing chamber 20. The breech closure is herein shown in the form of a, breech bolt 6 which is movable from open to closed position as usual in firearms, said bolt being backed by the usual recoil spring, which however, is not herein shown. The firearm illustrated is a magazine arm, and a portion of the magazine is shown at 24.

The firing pin which is carried by the breech bolt 6 is shown at 8 and it is provided with the forwardly extending end H which is adapted to have a detonating impact against the primer of the cartridge 2t. Said firing pin is carried by a rocking element 1 which is received within a recess 253 with which'the front end of the breech bolt is provided, and it operates through an opening 28 formed in the face of the bolt and communicating with said recess 29. The firing pin 8 i shown as pivotally mounted on the rocking member '5, said member being slotted at its lower end to receive the firing pin and being provided with a pivot pin 9 on which the firing pin is mounted. The rocking member i normally rests loosely against the bottom wall 33 of the recess 29, said wall constituting a, rocker-supporting face for the rocking movement of the rocking member as will be presently described.

The rocking member 7 has a flat rear surface ll at its lower portion to which the firing pin is pivotally connected, and the rear face of the upper end of said rocking member presents a curved surface FR which has a rocking contact with the face 33 of the recess 29 as will be presently described. The rocking member I is normally held in its retracted position shown in Fig. 1 by means of a spring In, one end of which is received in a recess 3| formed in the front face of the rocking member 1 and the other end of which is received in a recess 32 formed in the breech bolt.

Means are provided for giving the rocking member 1 its rocking motion over the face 33 and while the character of such means may vary in different types of firearms, yet in connection with the firearm herein illustrated the rocking member l is given its rocking movement during the final closing movement of the breech bolt. Such rocking motion of the member 1 is a quick rocking motion on the face 33 of the recess 29, thereby projecting the end H of the firing pin forwardly through the opening 28 and into detonating contact with the primer of a cartridge 2| in the chamber 20.

Such means is in the form of an abutment or stop member l4 carried by the receiver and having a portion l3 adapted to engage the face I2 at the outer end of the rocking member I during the final closing movement of the breech bolt and just before the bolt is fully closed. The engagement of the face :2 with the abutment or stop member I will give a counterclockwise rocking movement to the rocking member I during which the curved face IR of the rocking memher will have a rocking or rolling motion on the flat supporting face 33, such rocking motion obviously moving the firing pin 8 forwardly relative to the bolt.

The rocking motion of the rocking member 1 is similar to that of a rocking chair when it is being rocked on the fioor, that is, the curved face IR of the rocking member ha a sort of rolling motion along the supporting face 33 of the breech bolt, during which rolling motion the point or line of contact between the faces 'iR and 33 advances along both faces. The fulcrum about which the rocking member is turned at any given instant is the line of contact between said faces IR and 33, and during the operative rocking movement of the rocking member 7 by which the end II of the firing pin is given its detonating impact against the primer, such fulcrum progresses from a point near the center of the rocking member toward the outer end thereof. The fulcrum point about which said rocking member I turns during its rocking motion will thu s lift progressively rapidly toward the outer or upper end of said member I as the rocking motion continues, and because of this the lever arm of the member I which carries the firing pin is one which has a progressively increasing length during such rocking motion. This result in giving to the firing pin an accelerated operative movement relative to the bolt.

The striker abutment or stop member I4 is shown as occupying a recess 38 with which the receiver is provided and as having rigidly secured thereto a button element I5 which is of a size to span the recess 30. Inthe construction shown the recess 30 is somewhat longer than the abutment or stop element, and said element is backed by a spring which normally holds it in its operative position shown in Fig. 1. For this purpose, there is provided a pin i8 operating in a recess I! with which the barrel 5 is provided, said pin having a duced portion I9 that is fitted into a recess in the abutment or stop element It. The pin I8 is backed by a spring I6 which occupies the recess.

In the operation of the firearm when the breech bolt 6 is in its fully retracted position, the top cartridge 2| M in the magazine 24 will move upwardly into a position to. be engaged by the bolt as it moves forward and during such forward movement of the bolt it will strip the top cartridge from the magazine as shown in Fig. l and carry the cartridge into the chamber 26 of the barrel. During this movement, the rounded end of the bullet 22 is guided into the chamber by the usual bevel portion 23 of the barrel. Fig. 1 shows the cartridge just entering the chamber 2 and it also shows the firing pin in its retracted position. Just before the breech bolt reaches its closed position, the portion 63 of the abutment member I4 will engage the face I2 of the rocking member 7 and during the very final closing movement, the rocking member I will be turned .by its engagement with said abutment member I4, thereby projecting the firing pin forward through the opening 28 and into contact with the primer in the cartridge 2 I. The bolt is moved rapidly forward by its recoil spring, and the im pact of the stop member I4 against the rocking member I is such as to give the firing pin a hammer-like impact against the p The hammer-blow effect of such impact is increased by reason of the fact that during the rocking motion of the member I the fulcrum point is rapidly and progressively moving toward the outer end of said member.

The detonation of the cartridge will occur during the forward movement of the bolt and just before it is fully closed. The gas pressure developed by the firing of the cartridge not only forces the bullet through the barrel but it also applies a back pressure to the bolt which is still moving forward. By the time the bullet has been discharged from the barrel and the bolt has reached its closed position, the residual pressure will drive the bolt backward to its open position against the action of its recoil spring. When the bolt reaches its open position, the next cartridge ZIM has moved up into position to be engaged by the bolt during its next forward movement, and the operation above described will be repeated.

Since the detonation of the cartridge occurs during the forward movement of the bolt and just before it is fully closed, the pressure developed by such detonation will have a retarding action on the last increment of the closing movement of the bolt, thereby producing a cushioning effect for the bolt.

The rocking motion which the rocking member 5 has when it is engaged by the stop member I4 serves to compress slightly the spring I0, and the resiliency of this spring together with the pressure against the firing pin produces a rebound action of the firing pin which restores it to its normal position immediately after the detonation takes place.

The recess 29 in which the rocking member I is loosely received, may be provided for in various ways. As herein shown, the breech bolt is made with a vertically disposed slot in its end face and the bottom of the slot is permanently closed by a plug or block member 6a which forms the bottom of the recess. The front portion of the slot is also closed by a block 5b which is permanently secured in the open end of the slot and which has the opening ZSthrough which the end I I of the firing pinv is projected. This block 82) terminates at a point below the upper side of the breech bolt thereby leaving the opening 21 to receive the portion I3 of the abutment or stop member during the final closing movement of the breech bolt.

I claim:

1. A fire arm comprising a barrel having a firing chamber, a breech closure movable from open to closed position and having a rocker-supporting face extending transversely to the direction of movement thereof and facing toward the firing chamber, a rocking member, one face of which has a convexly curved section adjacent one end thereof, a firing pin carried. by the other end of the rocking member, said breech closure having provision for supporting the rocking member with its said face loosely resting against and for rolling contact over said rocker-supporting face, and means to engage the first named end of said rocking member and to rock said member over the rocker-supporting face with a rolling as distinguished from a sliding contact therewith and thus impart to the firing pin an accelerating detonating movement.

2. A fire arm comprising a barrel having a firing chamber, a breech bolt movable from open to closed position and having a rocker-supporting face extending transversely to the direction of movement thereof and facing toward the firing chamber, a rocking member having a face which is convexly curved at one end thereof, said breech bolt having provision to support the rocking member with its said face loosely resting against and for rolling contact over said rocker-supporting face, a firing pin carried by the other end of the rocking member, and means to deliver a hammerlike blow to the first named end of the rocking member and to give said member a rolling motion over said supporting face, during which rolling motion the line of contact between said convexly curved face of the rocking member and the supporting face, which line of contact constitutes the fulcrum about which the rocking member turns, advances progressively toward the first named end thereof and the length of the lever arm of said member which carries the firing pin is correspondingly progressively increased,

3. A fire arm comprising a barrel having a firing chamber, a breech bolt movable from open to closed position and having a rocker-supporting face extending transversely to the lengthwise dimension of the bolt and facing toward the firing chamber, a rocking member, said bolt having provision for supporting the rocking member loosely against said face, a firing pin carried by the rocking member, one of the contacting faces of the breech bolt and rocking member being a flat face and the other having a convexly curved portion, and means operative during the final closing movement of the breech bolt to engage the rocking member and to give the latter a rolling movement over said rocker-supporting face, during which there is a rolling contact between the convexly curved face and the flat face and the firing pin is given an accelerated detonating movement.

4. A fire arm comprising a barrel having a firing chamber, a breech bolt movable from open to closed position and having a rocker-supporting face extending transversely thereof and facing toward the firing chamber, a rocking member loosely resting against said face, the face of said rocking member which contacts with said rockersupporting face having a convexly curved portion at one end, a firing pin carried by the rocking member, means operative during the final closing movement of the breech bolt to engage the rocking member at a point spaced from the firing pin and to give the rocking member a rolling motion over said supporting face with the convexly curved section of the rocking member having a rolling, as distinguished from a sliding, contact with said supporting face.

5. A fire arm comprising a receiver, a barrel having a firing chamber, a breech bolt movable from open to closed position and having a recess adjacent its front end, one wall of which recess constitutes a rocker-supporting face which extends transversely of the direction of movement of said breech bolt and faces toward the firing chamber, a rocking member loosel received in said recess and resting against said supporting face, the face of said rocking member which contacts said supporting face having a convexly curved portion, a stop member carried by the receiver and adapted to engage said rocking memher during the final closing movement of the bolt, and give said member a rolling as distinguished from a sliding motion over said supporting face, and a firing pin actuated by such rolling motion.

6. A fire arm comprising a receiver, a barrel having a cartridge chamber, a breech bolt movable from open to closed position and provided adjacent its front end with a recess, the bottom wall of which extends transversely of the direction of movement and faces toward the cartridge chamber, a rocking member in said recess resting loosely against said bottom wall, the face of the rocking member which engages said bottom Wall being convexly curved adjacent one end thereof, a firing pin at the other end of the rocking memher, a yielding stop member carried by the receiver in position to engage the first named end of the rocking member during the final closing movement of the bolt, and to give the rocking member a rolling motion over the bottom face of the recess and thus impart to the firing pin a primerdetonating impact.

GEORGE NORMAN ALBRE-E. 

